The present disclosure herein relates to a wavelength combiner and an arrayed waveguide grating (AWG) having the same, and more particularly, to a wavelength and having a rib waveguide and an AWG.
In the fields of optical communication and photonic integrated circuit (PIC), an optical device for the muxing/demuxing of a signal may include an arrayed waveguide grating (AWG), Echelle grating, ring filter or Mach-zehnder interferometer. Among others, the AWG is a wavelength division multiplexer (WDM) device that is being most widely used. In the field of AWG, an AWG that is based on silica and an AWG that is based on silicon (Si) or indium phosphide (InP) having a higher refractive index than the silica are being researched.
When a material having a high refractive index is used, the size of an AWG device may decrease because a radius of curvature minimizing light loss decreases. The input loss of a general AWG is about 3 dB. Since a silicon AWG has a large coefficient of expansion, it shows a characteristic that the output spectrum of the AWG is sensitive to temperature. Thus, there is a need for the silicon AWG to be designed to operate irrespective of temperature. To this end, when the AWG is designed, it is general to make the output spectrum of the AWG flat so that an output is constant, even when temperature varies and thus the wavelength of the output spectrum varies.